boulton



('No Model.)

1v1. P. W. BOULTON xv E. PERRETT. SUPERHEATED STEAM ENGINE.

No. 312,959. Patented Feb. 24,1885.-

UNITED STATES PATENT OEETCE,

MATTHEV PIERS WATT BOULTON, OF TEW PARK, COUNTY OF OXFORD, AND EDWARDPERRETT, OF WESTMINSTEE, COUNTY OF MIDDLESEX,

ENGLAND.

SUPERHEATED-STEAMVENGINE.

SPECIFICATION farming part of Letters Patent No. 312,959, dated February24, 1885.

Application filed June 152, 1884. (No model.) Patented inEnglandDecember 18, 1883, No. 5,797; in France June 12, 1884, No. 162,704,- inGermany June 15, 1884, No. 30,080; in Belgium June 19,1834, No. 65,533,and in Italy June 30, 1884, XXXIII, 400.

To @ZZ whom t may concern:

Be it known that we, MATTHEW Pri-insW in Great Britain, No. 5,797, datedDecember 18, 1883,) of which the following is a specification.

Our invention relates to a steam-engine worked by steam which, previousto performance of work in the engine, is highly superheated.

IVe will describe one form and arrangement of engine according to ourinvention, referring to the accompanying drawings.

Figure 1 is a vertical section, partly in elevation, and Fig. 2 is aplan, partly in section.

The engine consists of the following principal parts: a steam boiler orgenerator, G, a heater in duplicate A and A2, two singleacting hotcylinders-a smaller, B', and a larger, BL-and an ordinary double-actingsteam-cylinder, C. The pistons of the two cylinders B and B2 areconnected to one crank, and the piston of C is connected to a crank atabout right angles to the former, both cranks being on a shaft, F, onwhich there are suitable cams or eccentrics for working the valves ofthe cylinders.

The boiler G may be of any known construction capable of generating high-pressure steam, and provided with the usual feed, gage, and valvefittings. From its steamspace a pipe, g, provided with a shut off valve,leads to three branches, g gZ g3, each having a shutoff valve, g',leading to the heater A, g2 leading to A2, and g3 to the pipe supplyingthe cylinder B. Each of the heaters A A'L is of the same construction asthat describedV and claimed in the specification accompanying ourapplication,now pending,for Letters Patent for caloric orhot-air engine,No. 134,703, and is therefore not herein claimed. The heater A is anupright cylindrical vessel having in its lower part a fireplace, a, theaccess to which can be tightly closed by a cover, a. Above thetire-place there are superposed a number of circular slabs, a2, offire-brick or equivalent refractory material,perforated by numerousholes, and having spaces between them for free passage of air, steam, orother gaseous iuid.

Instead of using perforated slabs, ordinary fire-bricks may be built upwith interstices between them.

Above the refractory material there is-a brick dome, c, from theperiphery of which a metal plate partition, ci, extends down nearly tothe bottom of the vessel, dividing into two annular channels the spacesurrounding the refractory structure. From the top of the vessel thereis a passage to a chimney, E, provided with a valve, a5, by which. itcan be tightly closed. Two pipes, g and a?, each provided with ashut-off valve, communicate with the interior of the vessel-the one atthe top and the other in the lower part. The other heater, A2, is inevery respect similar to A', and the two are worked alternately in thefollowing manner: The valves of g and al of A being closed, and the doorc and chimney-valve c5 being open, a iire is kept fior several hoursburning in the fire-place c. The fiames and hot products of combustionpass up through the holes or interstices of the firebricks ai, aredeflected by the dome c down the annular channel within the partitionc4, then ascend outside c4, and pass away by the chimney E. Vhen thefire-bricks ai are thus heated, the door c and chimney-valve 'a5 aretightly closed, the valves of g and a7 are opened, steam from the boilerG enters by g', passes down the annular channel outside of ai, ascendsinside c4, is deflected by the dome a, passes through the interstices ofthe hot fire-bricks a, becomes superheated,and issues by the pipe ci.Vhile A is being heated by re within it, A2, which had been previouslyheated, is employed for heating the steam,

and when A is sufficiently heated and A2 cooled their operation isinverted-that is to say, AIl is now heated by fire within it,and A isemployed to heat the steam. The annular channels on each side ofat, bymaintaining a l lower part of the cylinder D, and this steam jacket ofsteam not superheated Vbetween the outer casing and the hot brickswithin, reduces loss of heat by conduction and radiation.

The cylinder B is made in two parts. The upper part, which receives thehot steam, consists of two metal cylinders separated byafectly-conducting material, such as asbestus sheet, to lessen as much aspossible conduction of heat from the one .part of the cylinder to theother. The lower part of the cylinder is tted with a packed piston, b3,having projecting up from it a shield, b, deep enough to occupy all thehot part of the cylinder when the piston is up.

To the under side of the piston b3 is attached a block, b5, of wood orother equivalent bad conductor of heat, which occupies the lower part ofthe cylinder when the piston is up. There are two valves, DE and bl,worked by cams or eccentrics on the shaft F, to govern passages to andfrom the upper end of the cylinder B. The passage of bf communicates byapipe, 06, with the branches a7 from the two heaters A A2, each of whichbranches, as already mentioned, can be closed by a shutoff valve.Thepassage of bl communicates by a pipe, bw, with the lower part of thecylinder B2. lThis cylinder is similar to B', but inverted, and itpreferably has under it, at b, a small fire-place, or it might begas-burners, to keep the bottom hot. From the lower part of B2 there isa passagel governed by a valve, c, which is worked by an eccentric orcam on the shaft F. This passage leads toa reservoir, c2, forming acasing, which surrounds the cylinder C, and communicates with the jacketof itsslide c. The reservoir c2 may be kept hot by passing the hotproducts of combustion by the pipe i5 from. the fire or burners bthrough a space, c, below the reservoir, these products escaping by apipe, c6. In the drawings this lreservoir is shown encompassing thecylinder C; but it may be a separate vessel placed in any convenientposition.

The piston and piston-rod of the cylinder G may be of ordinaryconstruction. In the drawings,` however, we have shown an arrangementfor -keeping the piston hot. For this purposethe piston is hollow andthe pistonrod-is tubular with a smaller tube inside of it. The tubularpiston-rod has attached to it besides its cross-head d a smallerhollowpiston,

d, working in a cylinder, D, which also servesnds its way, by lateralholes a: in the tubular piston-rod,down the annular space therein, tothe interior of the piston of C. The water of condensation passes up theinternal tube of the piston-rod into and above the small piston d and isdischarged at d3.

From the slide facing of the cylinder C there is a passage, cl, for theexhaust-steam, which may be either blown off or condensed.

The above-described plan of warming the piston is more particularlyuseful if a further or fourth cylinder is added, in which the eX-pansion of steam is continued. 'It will be understood that such acylinder may be added to the construction shown in the drawings. As itwould not differ from cylinders ordinarily used, it has not been thoughtnecessary t0 show it. l rlhe operation of the engine is as follows:Steam generated at high pressure in G passes through one or other oftheheaters AAi, becoming superheated. It acts first in the cylinder B, andthen, expanding, acts in the larger cylinder B2. Reduced in temperatureby expanding and performing work, it iiows into the reservoir ci, andthis supplies thecylinder C as an ordinary steam-cylinder is supplied.The heat of the steam supplying the cylinder B can be tempered byadmitting with it more or less steam not superheated, but led directfrom the generator Gr by the pipe g3. i

Although we have shown in the drawings and described a particular formof engine and a particular arrangement of its main parts, it is obviousthat these parts could be variously proportioned, constructed, andarranged to operate in the manner described. Although we have describedtwo heaters, A A2, arranged to act alternately so as to provide forcontinuous action of the engine, it is obvious that when the action isintermittent a single heater maybe used. For instance, for an engineworking only during the day, one heater will suffice, this being heatedduring night hours, and being used for superheating during the day.

Having thus described the nature of our invention and the best meansweknow of carrying it out in practice, 'we claim- 1. In engines workedlby steam or vapor, the combination of a boiler or generator with aheater containing tire-brick or suitable refractory material disposedwith numerous in,- terstices, the whole arranged and operating in suchmanner that the heater at one time is heated by tire under kordinarypressure, and afterward it is put in communication with the boiler andengine, so that the steam Orvapor on its way from the boiler to theengine passes through the interstices of the heater,

IIO

becoming thereby superheated, and enters the steam-boiler, G, a heateror heaters, A A2, a, two subscribingwitnesseshis l2thdayof May, pair ofhot-steam cylinders, BB2, andan ordi i A. D. 1884. nary steam cylinder,C, with theil1 pipes, 1 valves, and eonnecbions,ar1anged and operat- 1 5ing substantially as described. iVitnesses:

In testimony whereof We have signed our OUVER IMRAY,

l JNO. P. M. MILLARD.

M. P. W. BOULTON. FDVARD PERRETT.

names to this specification, in the presence of

